Larry mows lawns for $50 an hour. Last week, he gave all his customers a 20% discount off his hourly rate. Mrs. Grinnell hired Larry last week to mow her lawn, and Larry applied a 10% new customer discount to his already discounted rate. If Larry worked on Mrs. Grinnell's lawn for 3 hours, how much does Mrs. Grinnell owe Larry?

If Larry worked on Mrs. Grinnell's lawn for 3 hours, Mrs. Grinnell would owe Larry $108.

Step-by-step explanation:

You have to find the total amount Larry would receive with $50 an hour:

$50*3=$150

Now, you have to calculate the amount with a 20% discount by calculating the 20% of $150 and subtracting that amount from $150:

$150*20%=$30

$150-$30=$120

Then, you have to calculate the 10% of $120 and subtract that amount from $120:

$120*10%=$12

$120-$12=$108

According to this, the answer is that if Larry worked on Mrs. Grinnell's lawn for 3 hours, Mrs. Grinnell would owe Larry $108.